SIST EN 2436-005:2009

Overview

The SIST EN 2436-005:2009 standard, established by the European Committee for Standardization (CEN), defines the technical requirements for a two-component, cold curing, chromate-free, corrosion-resistant primer designed specifically for aerospace applications. This primer is applicable for exterior use and accommodates surface preparation tolerance, making it versatile in practical aerospace coating processes. The primer can be based on either epoxy or polyurethane chemistry and is intended for use with or without a topcoat finish on aluminium alloy substrates.

This standard supports the aerospace industry's move toward environmentally safer coatings by eliminating chromate corrosion inhibitors traditionally used in primers. It ensures durability and corrosion resistance while maintaining cold curing properties beneficial for operational efficiency.

Key Topics

• Primer Composition:

  • Two-component system (base and activator) mixing epoxy or polyurethane resins.
  • Chromate-free formulation, promoting environmental and health safety.
  • Includes pigments, fillers, and solvents tailored for aerospace-grade corrosion resistance.

• Surface Preparation and Tolerance:

  • Designed to tolerate varying degrees of aluminium alloy surface preparation following EN 3837 Process D and ISO 3270.
  • Supports use on aluminium alloys like 2024-T3 clad for optimal adhesion and corrosion protection.

• Technical Requirements:

  • Dry film thickness controlled at 20 ± 5 µm.
  • Physical properties including viscosity, sedimentation stability, and gloss controlled within strict limits.
  • Mechanical properties such as adhesion, scratch resistance, and bend test performance ensure primer robustness.
  • Environmental resilience including heat, cold, fluid resistance, water behavior, and filiform corrosion resistance tested through comprehensive qualification methods.

• Testing and Quality Assurance:

  • Batch release testing for consistency in production.
  • Qualification testing covering physical, mechanical, chemical, and environmental criteria to validate performance.
  • Compliance with related aerospace paint and varnish standards such as EN 3840 and EN 2434-004.

• Application and Processing:

  • Cold curing at room temperature within a drying time frame ideal for aerospace manufacturing environments.
  • Flexible application conditions with variable curing times under specified ISO 3270 controlled humidity and temperature.

Applications

SIST EN 2436-005:2009 facilitates the use of chromate-free primers in many critical aerospace exterior components requiring high corrosion resistance. Common application areas include:

• Aluminium aircraft structural components, such as airframes and control surfaces.
• Protective primer layers for aerospace alloys exposed to harsh environmental conditions.
• Systems requiring adhesion tolerance related to surface preparation variability to improve operational efficiency.
• Components where chromate avoidance is mandated due to environmental, health, or regulatory concerns.
• Aerospace parts with or without subsequent application of polyurethane or epoxy-based finishes.

This primer standard supports aerospace manufacturers aiming to meet strict safety, environmental, and durability standards without compromising corrosion protection capabilities.

Related Standards

• EN 3837: Specifies nature and method for surface preparation of aluminium alloy test pieces used in paint qualification.
• EN 3840: Technical specification covering aerospace paints and varnishes, including testing methods relevant for batch and qualification testing.
• EN 2434-004: Two-component cold curing polyurethane finish complementing the primer for exterior aerospace parts with high flexibility requirements.
• ISO 3270: Defines conditioning and testing parameters such as temperature and humidity for paints and primers.
• EN 2379: Fluids specification standard for evaluating non-metallic materials, including primers’ resistance to chemical exposure.
• EN 4385: General organization of aerospace non-metallic material standards illustrating linkages between multiple standards.
• TR 7000-9: Technical report providing rules for drafting and presenting aerospace material standards including paints and varnishes.

Keywords: EN 2436-005, aerospace primer, chromate-free primer, corrosion resistant primer, two component primer, cold curing epoxy primer, polyurethane primer, aerospace coatings, aluminium alloy primer, surface preparation tolerance, aerospace paint standards.